Monoclonal antibodies (mABs) have been instrumental in many major advances in our understanding of infectious diseases, hypoimmune disorders, hyperimmune disorders and carcinogenesis. MAbs have progressively improved laboratory diagnosis of infectious and immune diseases; they also greatly aid diagnosis, prognostication and following of malignant diseases. More recently mAbs have lead to FDA approved in vivo diagnostics. Currently mAbs are being tested in numerous clinical and preclinical trials as in vivo therapeutics. Numerous medically, scientifically and commercially important products are mAbs. Production of mAbs is thus of major importance. Nevertheless our ability to control hybridoma growth and our understanding of the relationship between hybridoma growth and mAb production is incomplete. The proposed studies examine the ability of a regulator of cell growth (CeReS) to control the reproduction of hybridoma cells, synchronize their metabolic activity and stimulate the production of mAbs. CeReS reversibly holds cells in G1. Significant circumstantial data in other systems indicate that cells in G1 produce more mAb. The proposed studies are expected to: 1) establish the cell cycle dependence of mAb. The proposed studies are expected to: 1) establish the cell cycle dependence of mAb production, 2) provide researchers and manufacturers methods to turn cell reproduction off without altering nutrient supply or applying toxic drugs and 3) dramatically increase mAb production. PROPOSED COMMERCIAL APPLICATION: Increased ability to produce many clinically important materials is expected to decrease cost, increase purity, increase culture reproducibility, and increase mAB production.